This invention relates to a method for in-situ waterproofing of underground pipes by causing a wheeled vehicle carrying a rotary sprayer to pass through a length of pipe while spraying a fast setting organic waterproofing compound onto the interior of the pipe.
Underground sewer and storm drainage pipes are typically made of concrete or masonry. As they get older, they become more and more permeable. Also, it becomes more and more likely over time that joints will have opened or separated due to ground movement. The result is pipes which leak water or other materials, absorb water from the outside and are susceptible to collapse and crumbling due to the deterioration of the concrete or masonry walls. Once these pipes are installed underground they are extremely difficult to repair even though access through manholes and the like may be provided at intervals such as 50xe2x80x2 to 300xe2x80x2. Often the repair of such underground pipes involves digging them up and replacing them.
The method of the present invention, generally described, involves placing a rotary spray device capable of generating a cylindrical; i.e., 360xc2x0 spray pattern into a pipe to be lined on the interior surfaces thereof, using the device to spray a fast setting organic compound onto the interior of the pipe or line while causing the device to travel through at least the length of the pipe and, thereafter, removing the device from the pipe.
It has been found that through the proper selection of materials to be sprayed, typically using air for atomization, an extremely fast setup may be achieved which prevents sagging or dripping of the material from the interior surfaces of the line or pipe. Materials and air are typically supplied to the spray device from the surface through supply lines and the device, although it may be self propelled, it is typically pulled through the lines for a length of between, for example 50xe2x80x2 and 300xe2x80x2.
The apparatus aspect of the present invention provides a wheeled carrier which, as hereinafter described is preferably constructed in two longitudionally spaced parts, a rotary spray device of conventional design mounted on the carrier between the spaced parts for rotation about an axis which is parallel to the longitudinal axis of the pipe or line through which the vehicle is moved, thereby to provide a cylindrical spray pattern. The apparatus further comprises a motor, typically an air motor, mounted on the carrier for rotating the spray device about said parallel axis and one or more supply lines for conveying air and material to the spray device from a remote supply location.
As indicated above the wheeled carrier and the rotary spray device are caused to be moved through a length of pipe or line and the supply lines and motor are operated to cause a cylindrical spray pattern of material to be deployed from the device to the interior surfaces of the pipe through which the device moves. By using a fast setting two part compound of organic materials, use of the apparatus can create a self-supporting waterproof structure within the interior of the old and potentially crumbling concrete or masonry pipe or line.